Attachment on flat knitting machines for holding down the fabrics



Jan. 12, 1937. w. HEINlTZ 2,067,842 ATTACHMENT ON FLAT KNITTING MACHINES FOR HOLDING DOWN THE FABRICS I Fil ed June 5, 1936 4 Sheets-Sheet 1 Jan. 12, 1937. w. HElNlTZ 2,067,842

ATTACHMENT ON FLAT KNITTING MACHINES FOR HOLDING DOWN THE FABRICS Filed June 3, 1936 4 Sheets-Sheet 2 iffy.

Jan. 12, 1937. w. HEINITZ 2,057,842

ATTACHMENT ON FLAT KNITTING MACHINES'FOR HOLDINGDOWN THE FABRICS Filed June 3, 1956 4 Sheets-Sheet 5 Jan. 12, 1937. w HElNlTz 2,067,842

ATTACHMENT ON FLAT KNITTING MACHINES FOR HOLDING DOWN THE FABRICS Filed June 3, 1936 4 Shepts-Sheej 4 [/Weflfw": Waldemar Hem/Z2 Patented Jan. 12, 1937 UNITED STATES PATENT OFFICE ATTACHMENT N FLAT KNITTING MA- CHINES FOR HOLDING DOWN THE FAB- RIOS Application June 3, 1936, Serial No. 83,364 In Germany June 18, 1935 7 Claims. (Cl. 66 -82) The present invention relates to attachments on flat knitting machines for holding down the heel portions in the manufacture of stockings in a single operation on machines in which the needles used for producing the instep portion are placed in suspense during knitting of the heel portions of the stockings.

During the manufacture of the heel portions on straight knitting machines in which the needles, producing the instep portion, are placed in suspense on knitting the heel portions, the jack sinkers and dividers may, on their forward movement, easily damage the fabric due to the fact, that at this time the fabric is not held down by the nib of the sinker. This danger particularly exists at the inner edge loops of the heels, i. e. in

the range of the corners of the heel.

The main object of the present invention is to obviate the above mentioned drawback and to obtain this end holding down devices, one for the inner side of each heel portion, are provided. During knitting of the leg portion of the stocking, the holding down devices occupy a position of rest outside the loop forming parts, Whereas, during the manufacture of the heel portions, they are brought in operative position by swinging them about their supporting shaft, so that they hold the fabric off the jack sinkers and dividers by pressing upon the fabric from above.

A pair of holding down devices is required for each division of the knitting machine. To prevent damages of the swungout needle bar by the associated pair of holding down devices in case one or the other division fails, all the holding down devices are independently swingably arranged, so that, on failure of any division the machine can continue the operation without loss of time, as only the holding down devices associated to this particular division need to be brought in the position of rest or out of operation.

As soon as the operation of the holding down devices is finished, all the holding down devices may again be brought into the inoperative position or the position of rest by turning the shaft carrying them. Any holding down devices individually swung into the position of rest automatically are connected again to the shaft on turning the latter backwardly, so that then all the holding down devices again occupy a position in which they are adapted to be simultaneously brought into the operative position when the shaft, carrying them, is turned again.

To obtain edges of the heel portions free of objections which are of particular importance for looping the heel portions together, a plurality of holding down fingers may be provided at each arm and the fingers facing the centre of the fabric of these fingers and the next following may be provided with a hook for drawing off the fabric, instead of using simple holding down arms pressing upon the fabric.

The use of all the above mentioned holding down devices requires an exact adjustment of each arm or each finger with regard to the space between the sinkers, to exclude the danger of damaging the sinkers due to running of the latter against the holding down devices.

To prevent this troublesome and time wasting operation, resilient presser pieces, for instance bristles united to a brush, are, according to at the free end of the holding down arms,

whereby, without any adjustment of .the holding down device, damages of the jack sinkers and the dividers respectively by running against the presser pieces of the holding down device are prevented.

In the accompanying drawings some constructions of holding down devices according to the invention are shown by way of example.

In these drawings:

Fig. 1 is a plan View of a holding down device according to the invention,

Fig. 2 is a cross section on line II-II of Fig. 1, showing the loop forming elements of the knitting machine in elevation,

Fig. 3 shows a plan view of a modified construction of the new device,

Figs. 4-6 are cross sections through the devices shown in Fig. 3, illustrating the individual partsin the sinking-, press-, and knocking-oft position respectively,

Fig. '7 is a detail view,

Fig. 8 is a part sectional side elevation of a still further modified construction of the holding down device according to the invention,

'. also fixed to each arm I.

lever 5, fixed by means of a screw 4 upon the shaft 3, serves for rotating the latter. Rotatably mounted upon the shaft 3 at each division of the knitting machine are the bosses or sleeves 6 of two arms I of substantially Z- or S-shape to which the holding down means 8. proper are fixed by a screw 9 or the like. The sleeves 6 are held in a position exactly opposite the space between juxta-positioned jack sinkers I0 and dividers respectively by means of two adjustable rings II and I2 with associated screws- I3, I4 in such a manner, that, during the manufacture of the heel portions of a stocking, the holding down means 8 can press upon the fabric, forming the heel portions, at both sides of the instep portion of the stocking, the needles for producing same being placed in suspense.

Fixed by a screw I 5 to the middle part of each arm I, extending about in parallel to the shaft .3, is a leaf spring I6 the free end of which, directed towards the shaft 3, is formed as a hook IT. A notch I 8. is provided in the adjustable: ring I2 bearing against the inner surface of each pair of arms 1 of a division. Into this notch I9 the hook I! of the associated leaf spring I6 engages for rotatably connecting the arm I to the shaft 3.

During the manufacture of the leg portion of the stocking the holding down devices I, 8 occupy the position shown in dashand dotted lines in- Fig. 2 which illustrates an individual holding down arm in its inoperative position. By the hand lever 5 all the holding down devices I, 8 mounted upon the shaft 3 may in unison be brought out of their position of rest into the operative position in which, during the manufacture of the heel portions, they press upon the loops of the heel portions at both sides of the instep portion of the stocking the needles for knitting same being placed in suspense, thereby protecting these loops against damages by the sinkers. If the hand lever 5 is turned in the opposite direction, all holding down devices I, 8 are, after finishing of the heel portions, again brought into the position of rest shown in dashand dotted lines in Fig. 2.

Should for some reason one or the other division of the machine fail or become inoperative, the associated holding down arms may independently of .all others be returned or swung back into the position of rest, so that the operation of the knitting machine may be continued without loss of time. If an individual holding down arm is swung into the position of rest, the hook I! of the corresponding leaf spring I6 disengages, as shown in dashand dotted lines in Fig. 2, the notch I8 of the associated adjustable ring I2, whereupon, after finishing the heel portions and during the return movement of all the holding down devices by turning the hand lever 5, the hooks I1 of the leaf springs I6 of the; previously swung back holding down devices automatically again engage the notches I8 of the associated adjustable rings I2, whereby these holding down devices also are again connected to the-shaft 3, so that, by turning of the hand lever 5, all the holding down devices are again swung into the operative position.

In the construction shown in Figs. 3-7, a hook I9 is provided at each arm I at their sides facing each other. This hook is adapted to engage the edge loop of the inner heelportion and serves for drawing off the fabric. Fingers 2|]. serving for holding down the fabric only, are Instead of a single draw off hook I9, each arm I may also be provided with two juxta-positioned draw off hooks.

The press instruments 22, acting upon the frame needles 2I, are moved up and down in a well known manner'by a presser frame. The presser frame 23 carries arms 24 the free end of each of which is provided with a sleeve or boss 25. Screwed into an internal female thread of each sleeve or boss 25 is a screw 26 which is held in the adjusted position by means of a nut 21. The free end of the screw 26 serves as an adjustable stop which, however, may be of any other construction. At each division an arm 28 is mounted upon the shaft 3 the free end of which bears against the stop 26.

Fixed to the frame I of the machine are bearings 29 in which a shaft 30 is rotatably mounted. At each division, the shaft 30 carries two sleeves or bosses 3I each of which carries a plate 32. If the holding down devices I, I9, 20 are not used and occupy the position of rest, shown in dashand dotted lines in Figs. 3 and 4, the plates 32 occupy the position shown in full lines in these figures to prevent hurting by the draw off hooks I9.

The press instruments 22 are lifted and brought in front of the presser edge 33 of the sinker head for pressing oil the frame needles 2|. By the arms 24 carried by the presser frame 23 the arms 28 are simultaneously lifted, so that the draw ofi hooks I9 and the fingers 20 are, as shown in Fig. 5, also lifted and brought out of engagement or out of contact respectively with the fabric 34 indicated in dashand dotted lines.

After the pressing operation is finished, the press instruments 22 are returned again in the position of rest below the presser edge 33 and simultaneously the draw off hooks I9 and the fingers 20 which were out of contact with a fabric 34 are again brought into a position to engage the fabric and to bear against the latter respectively. During the now following knocking off of the loops by the knocking over bits 35, the draw off hooks I9,and the fingers 20 hold the fabric, so that, as shown in Figs. 6 and 7, the frame needles 2I, during the following locking-in operation draw off the fabric and the rows of loops, lying between the draw off hooks I9 and the frame needles 2I respectively, which are held down by the fingers 20.

During the then following sinking operation during which time the press instruments 22 lie below the presser edge 33, the draw off hooks I9 then repeated.

The drawing off of the fabric is therefore obtained in each newly formed course in the usual manner by the movement of the needles without altering this movement.

If the draw offand holding down devices I, I9, 20 are not in operation, the plates 32 are. as indicated already, brought into the position shown in Figs. 3 and 4 to cover the swung out draw off hooks I9 and holding fingers 20, so that hurting by the draw off hooks I9 is prevented.

As soon, however, as the formation of the heel portions is started, the shaft 30 must be turned, whereby the plates 32 are swung into the vertical position, shown in dashand dotted lines in Fig. 4, so that now the draw offand holding ,down devices I, I9, 20 may be swung into the operative position.

According to the construction shown in Figs. 8-10, two holding down arms 31 in each division are arranged upon the shaft 3 in the same manner as the arms 1 of the constructions already described. One of these arms 31 only is shown in the drawings. The arms 31 which in this case are formed as straight arms are provided with a downwardly extending projection 38 for connecting the leaf spring I6. The free end of each arm 31 carries a downwardly directed projection 39 to which, by means of a screw 40, a holding down means 4| is fixed. The free ends of the latter carry resilient presser pieces which preferably consist of bristles united to a brush 42. The brush 42 may be of any suitable shape and may for instance have the narrow form shown in the drawings. In particular, the brush 42 may have any width, so as-to engage the heel portions over their entire width.

According to Fig. 8,. the bristles are united to a brush 42 or the like, whereas according to Fig. 10 bristles folded to a U-shaped bundle 43 are fixed in the holding down device 4!.

During the manufacture of the heel portions breaking or damaging of the sinkers by the holding down devices is absolutely impossible, as the bristles of the brush 42 or the bundle 43 give way, as soon as the sinkers 44 come into contact with them. Consequently an exact adjustment and arrangement of the brushes 42 or bundles 43 is not required with this construction.

If the holding down devices are swung into the inoperativ'e position,'hurting of persons in charge of themachine is impossible, as in this position of the individual parts the bristles of the brush are directed upwardly.

Instead of bristles united to a brush, other presser pieces, for example of rubber, felt, or the like, may be used.

What I claim is:

1. An attachment for use in connection with straight knitting -machines on'which stockings can be made in a single operation and in which the needles adapted to produce the instep portion are placed in suspense during the knitting of the heel portions, comprising two holding down devices for each division of the'machine which, during the manufacture of the heel porfabric to hold the latter off the sinkers and dividers.

2. An attachment for use in connection with straight'knitting machines on which stockings can be made in a single operation and in which the. needles adapted to produce the instep portion are placed in suspense during the knitting of the heel portions, comprising arotatable shaft extending all over the length of the machine, holding'down devices arranged upon said shaft, two adjustable rings associated with'each holding down device to hold the latter against movement in the longitudinal direction of the shaft in a position adjusted with regard to the sinkers, a spring connected to each holding down device, a hook provided at the free end of each spring adapted to engage and disengage a notch in one of said adjustable rings to connect and disconnect'said holding down device to and from said shaft respectively, and a hand lever fixed upon said shaft for rotating the latter and simultaneously swinging the holding down devices.

3. An attachment for use in connection with straight knitting machines on which stockings each spring adapted to engage and disengage I a notch in one of said adjustable rings to connect and disconnect said holding down device to and from saidshaft respectively, each of said holding downdevices consisting of an arm and a finger connected to said arm.

4. An attachment for use in connection with straight knitting machines on which stockings can be made in a single operation and in which the needles adapted to produce the instep portion are placed in suspense during the knitting of the heel portions, comprising a rotatable shaft extending all over the length of the machine, holding down devices arranged upon said shaft, two adjustable rings associated with each holding down device to hold the latter against movement in the longitudinal direction of the shaft in a position adjusted with regard to the sinkers, a spring connected to each holding down device, a hook provided at the free end of each spring adapted to engage and disengage a notch in one of said adjustable rings to connect-and disconnect said holding down device to and'from said shaft respectively, a hand lever fixed upon said shaft for rotating the latter and simultaneously swinging the holding'down devices, and

swingably mounted plates. for covering said holding down devices in their position of rest, said holding down devices each consisting of an arm, a draw ofi hook provided at the free end of said arm at the side facing the fabric, and a plurality of holding down fingers also provided at the free end of said arm at the side of the draw off hook.

5. An attachment for use in connection with straight knitting machines on which stockings can be made in asingle operation and in which the needles adapted to produce the instep portion are placed in suspense during the knitting of the heel portions, comprising a rotatable shaft holding down devices arranged upon said shaft, two adjustable rings associated with each holding down device to hold the latter against movement in the longitudinal direction of the shaft in a position adjusted with regard to the sinkers, a spring connected to each holding down device, a hook provided at the free end of each spring adapted to engage and disengage a notch in one of said adjustable rings to connect and disconnect said holding down device to and from said shaft respectively, a hand lever ,fixed upon said shaft for rotating thelatter and simultaneously swinging the holding down devices, and swingably mounted plates for covering said holding down devices .in their position of rest, said holding down devices each consisting of an arm, two

draw off hooks provided at the free end of said extending all over the length of the machine,

arm at the side facing the fabric, and a plurality of holding down fingers also provided at the free end of said arm at the side of the draw off hooks.

6. An attachment for use in connection with straight knitting machines on which stockings can be made in a single operation and in which the needles adapted to produce the instep por-r tion are placed in suspense during the knitting of the heel portions, comprising a rotatable shaft extending all over the length of the machine, holding down devices. arranged upon said shaft, two adjustable rings associated with each holding down device to hold the latter against movement in the longitudinal direction of the shaft in 9.

position adjusted with regard to the sinkers, a spring connected to each holding down device and a hook provided at the free end of each spring adapted to engage and disengage a notch in one of said adjustable rings to connect and disconnect said holding down device to and from said shaft respectively, each holding down device consisting of an arm, a second arm carried by said first mentioned arm, and resilient presser pieces connected to the free end of said second arm.

7. An attachment as set forth in claim 6 in which each of said resilient presser pieces consists of bristles united to a brush.

WOLDEMAR HEINITZ. 

